Modular shielded patchord programming system



MODULAR SHIELDED PATCHCORD PROGRAMMING SYSTEM Filed July 8, 1966 1968 J. E. TAYLOR, JR

5 Sheets-Sheet 1 INVENTOR tid /v KZ'wzae/ Oct. 15, 1968 J. E. TAYLOR, JR 3,406,369

MODULAR SHIELDED PATCHCORD PROGRAMMQING SYSTEM 5 Sheets-Sheet 2 Filed July 8, 1966 f l I l hxm INVENTOR J/m fiffbwagfa z 6 ATTORNEYS Patented Oct. 15, 1968 3,406,369 MODULAR SHIELDED PATCHCORD PROGRAMMING SYSTEM John E. Taylor, Jr., 413 Pine Ave., Waynesboro, Va. 22980 Filed July 8, 1966. Ser. No. 563,852 24 Claims. (Cl. 33918) ABSTRACT OF THE DISCLOSURE A patchcord programming system employing a pair of electrically conductive boards having spaced apertures in substantial alignment. The boards are separated by a partitioning grid which is also conductive. Contact members which are insulated from one another project through the apertures of one board to the interior of the grid. Patchcords are selectively positioned in the holes of the other board to make electrical connections with desired contacts. The grid provides a shielding function between electrical connections. The patchcords are coaxial and have shield caps which engage their associated board to establish an electrical connection therewith.

This invention relates to a patchcord programming system and, more particularly, to a system which is modular in concept and which provides improved cross-talk and attenuation characteristics.

In the past, various programming systems have been devised for applications wherein the signal conductors comprise coaxial patchcords. However, major problems which have been encountered in the prior systems include those of high levels of cross-talk and attenuation, and low economy.

The present invention overcomes the shortcomings of prior arrangements by providing an improved shielding arrangement for reducing cross-talk between a plurality of contacts thereby permitting the patchcords to engage con tacts positioned in close proximity to one another.

Another object of the invention is to provide an improved system for grounding the shield caps of each of the coaxial patchcords, as well as grounding the shielding arrangement between the contacts to which the patchcords are joined.

Ancillary to the foregoing, it is a further object of the invention to provide an improved coaxial patchcord shield cap for positively locking a patchcord to the modular contact unit, aligning the central conductor of the patchcord with a contact, and insuring low electrical resistance between the shield cap and the ground path.

A still further object of the invention is to provide a modular shielded patchcord programming system which is easy to manufacture and assemble, and which is relatively low in cost.

Further objects and the entire scope of the invention will become more fully apparent when considered in light of the following detailed description of an illustrative embodiment of the invention and from the appended claims.

The illustrative embodiment may be best understood by reference to the accompanying drawings, wherein;

FIGURE 1 is a side elevation view of a basic unit which comprises the modular patchcord programming system;

FIGURE 2 is a fragmented view in perspective illustrating the contact assembly of the basic unit and the shielding arrangement therefor;

FIGURE 3 is a side elevation view illustrating the construction of a connecting portion of the coaxial patchcord for use in this system, and particularly, the shield cap thereof;

FIGURE 4 is a front elevation view of the coaxial patchcord illustrated in FIGURE 3; and

FIGURE 5 is a fragmented view in perspective of an alternative embodiment of the invention illustrating the terminal assembly of the modular system and a shielding arrangement therefor.

Briefly, the invention comprises a first molded conductive board having a plurality of spaced apertures therein. A paddle contact spring projects through each of the apertures and is partially embedded in an insulator within the respective aperture such that the contact spring is fixed to the conductive board, but is insulated therefrom. A grid of partitions, formed of electrically conductive metal, is attached to this conductive board so as to isolate each of the contact springs from one another within compartments formed by the grid. A second molded conductive board, having apertures in substantial alignment with those of the first board, is positioned in contact with the partitions on the opposite side of the grid from that which engages the first board. Consequently, the second board'is conductively connected with the first board through the grid. To effect a connection with a particular contact spring, a coaxial patchcord tip is inserted through the appropriate aperture in the second conductive board. The shield cap of the patchcord is provided with a pair of circumferential ribs which engage the second conductive board within the chosen aperture so as to align the'central conductor of the patchcord in engagement with the selected contact spring, as well as to form a low resistance electrical contact with the conductive board. The shield cap also includes a third circumferential rib mounted on flexible fingers at the outer end of the shield cap. This third rib is positioned to extend just beyond the second conductive board when the patchcord is fully inserted therein and is dimensioned such that as the flexible fingers expand outwardly, the rib locks the patchcord to the board until such time as suflicient force is applied to the patchcord so as to depress the flexible fingers and release the third rib from locking engagement with the board.

Referring now to the drawings, the invention Will be described in detail. In FIGURE 1, there is illustrated a unit which comprises the basic modular shielded patchcord system element. Although only a single unit is represented, it will be apparent that any number of such units may be combined in modular fashion within a suitably designed frame. Since such framework is conventional, no description thereof is required.

Briefly, the modular unit shown in FIGURE 1 includes a first conductive board 10 which is preferably fabricated by molding a conductive plastic, such as a filled epoxy.

The molded board 10 is provided with a plurality of apertures 12 which are arranged in coordinate fashion with respect to the board. Insulating plugs 14 are inserted within the apertures. These plugs serve to support and attach to the conductive board 10 contact members, indicated generally at 16, which project through the plugs 14 and the apertures 12. The contact members are preferably of the type having a terminal portion 18 extending below the conductive board 10 and a paddle contact spring portion 20 projecting upwardly therefrom. A partitioning structure, indicated generally as 22 in FIGURE 2, is mounted to the conductive board 10 and serves to electrically shield the paddle contacts 20 from one another. The partitioning structure comprises a grid-like assembly of conductive metallic strips 24 and 26 which are orthogonally related so as to define a plurality of compartments 28 within each of which a paddle contact 20 is housed in spaced relation with respect to strips 24 and 26. The strips 24 and 26 are of greater width than the lengths of the projecting paddle contacts 20. Consequently,

' 3 the partitioning structure serves to electrically shield the paddle contacts from one another.

The molded conductive board 10 is provided with slits 30 at its edges. Although only one of such slits is shown in FIGURE 2, it will be apparent that any suitable number may be utilized so that each slit may receive a tab portion (not shown) extending from the partitioning structure in order to secure the latter to the conductive board 10. This insures that the partitioning structure '22 is electrically and mechanically connected to the conductive board 10.

A second conductive board 32 is positioned on top of the partitioning structure 22. Board 32 may also be electrically and mechanically connected to the partitioning structure in the same manner as just described with reference to the conductive board 10. Preferably, however, the mechanical interconnection of the board 32 with board 10 and the partitioning structure 22 is achieved by means of end frames 34 which are attached to both boards 10 and 32. The interconnection is suggested by a cooperating relationship between shoulders provided on the frame elements 34 and the conductive boards 10 and 32, but since interconnection between the elements 34 and these boards can be achieved in any number of conventional ways, there is no need to describe the details in order to obtain an understanding of the invention. All that is necessary is to appreciate that partitioning structure 22 and boards 10 and 32 are interconnected in the basic modular unit.

The frames 34 are illustrated as having apertures 36 extending therethrough. These apertures are presented to suggest that a number of modular units may be interconnected to form an expanded modular shielded patchcord programming system. The interconnection can be achieved, for example, by a simple bolting arrangement.

To complete the disclosure, the patchcord by which the signals may be transferred from one contact terminal 18 to another will now be described. The coaxial patchcords are illustrated generally in FIGURE 1 at 38. Before considering in detail the improved structure of the patchcord utilized with this system, it should be pointed out that in operation the patchcord is inserted through apertures 40 provided in the molded conductive plate 32, which apertures are in substantial alignment with corre sponding apertures in conductive board 10. Consequently, with a coaxial patchcord inserted in an aperture 40, the central conductive tip 42 thereof projects downwardly into a compartment 28 so as to engage a paddle contact spring portion 20 of a contact member 16 thereby completing a conductive path between the corresponding contact terminal 18 and the tip 42 of the patchcord.

In FIGURE 1, a complete coaxial patchcord is illus trated. It is apparent that in the position shown, this patchcord provides an electrical path between the contact terminals 18a and 18b. Obviously then, a path from an external electrical component connected to terminal 18a to another component joined to terminal 18b may be completed by means of the appropriate insertion of a coaxial patchcord into the modular unit. Similarly, other electrical paths may simultaneously be completed in the same manner.

With the complete patchcord 38 inserted in the conductive board 32, its shield cap 44 is in conductive relationship with board 32. It is intended that in use the conductive board 10 be grounded. Therefore, the shield cap 44 is connected to ground through board 32, partitioning structure 22 and board 10. In this manner, the circuit through the coaxial patchcord 38 is completed.

The invention also contemplates the use of an improved patchcord structure. This structure is illustrated in detail in FIGURES 3 and 4 of the drawings. The C- axial patchcord comprises a central conductor 46 which is surrounded with an insulator 48, such as polyethylene. A braid 50 of conductive material is applied around insulator 48, and the entire construction is enclosed within a further insulator 52. At the extremities of the patchcord, conductor 46 is connected to the central conductive tip 42 which is partially embedded in an insulator 56 but which has an exposed end. A shield cap 44, which is preferably a screw machine part, is connected to the shield 50 and is mounted over the insulator 56, Shield cap 44 is provided with a plurality of radially spaced slots 58 extending longitudinally from one end of the cap to define a plurality of flexible fingers 60. Along the fingers the shield cap is provided with spaced circumferential ribs 62, 64 and 66, and rearwardly of rib 62, the shield cap 44 includes an enlarged cylindrical portion 68 which defines an annular shoulder 70 at its intersection with the forward portion of the cap. The cylindrical portion 68 is greater in diameter than the apertures 40 provided in conductive board 32. The reason for this will become apparent shortly.

The circumferential rib 66 is slightly greater in diameter than ribs 62 and 64 and is spaced such that the distance from the apex of rib 66 to the shoulder 70 is slightly greater than the thickness of the conductive board 32. The diameters of the circles defined by the ribs 62 and 64 are greater than that of the apertures 40 Within board 32. From the foregoing, it is apparent that when a coaxial patchcord 38 is inserted into an aperture 40 in board 32, the engagement of ribs 66 with board 32 results in the flexing of the fingers of cap 44 inwardly thereby reducing the diameter of the circles defined by ribs 62, 64 and 66. As the insertion progresses, the shoulder of the shield cap 44 finally engages the outer surface of board 32 thereby preventing further insertion of the patchcord. At this time, the apex of rib 66 extends beyond the plane forming the inner surface of board 32. Consequently, the flexible fingers 60 move outwardly causing rib 66 to engage the inner surface of board 32 thereby locking the patchcord to the conductive board 32.

The outward movement of fingers 60 also results in ribs 62 and 64 positively engaging the interior of the board 32 thereby forming low resistance electrical contacts between the shield cap 44 and board 32, as Well as insuring the alignment of the patchcord within board 32. Of course, since the apertures 40 are aligned with apertures 12 of conductive board 10, during insertion of the patchcord its conductive tip 42 engages the corresponding paddle contact spring 20 to complete a signal path. Overriding of the contact springs is prevented by the alignment arrangement just described.

To facilitate the insertion of patchcoard 38 into an aperture 40 in board 32, the forward surfaces 72 of rib 66 'are machined in a cam-like manner to cooperate with the slightly bevelled surfaces 74 at the outer surface of the conductive board 32.

To withdraw the patchcord from its locked relationship with the board 32, somewhat greater force must be exerted than is necessary to insert the patchcord. Extra force is required to depress the fingers 60 in the face of the increased resistance offered by the uncammed rear surface of rib 66 and the unbeveled surfaces at the inner face of board 32 adjacent the apertures 40. To assist the user in withdrawing the patchcord, a plastic gripping cap 76 is inserted over the cylindrical portion 68 of the shield cap 44 and the forward portion of the coaxial conductor.

In summary, a structure has been described which is modular in concept in that a number of the basic units may be mechanically interconnected to expand the programming system. The use of molded conductive boards which are electrically interconnected by a grid-like partitioning structure to shield the individual paddle contacts while simultaneously providing a low resistance ground path for the coaxial patchcord results in a structure having excellent cross-talk and attenuation characteristics. The patchcord structure itself results in the positive locking of the conductor in operative position with respect to a paddle contact and insures that the patchcord is properly aligned with the contact. The aligning feature of the patchcord also functions to provide a low resistance electrical 'path between'the shield cap of the patchcord and the conductive boards of the modular unit thereby contribut'ing to the low attenuation of the overall system.

The above-described embodiment is illustrative of a preferred embodiment of the invention but is not intended to limit. the possibilities of insuring the features of low cross-talk and attenuation and appreciable economy of construction. For example, it is contemplated in the alternative embodiment of the invention illustrated in FIG- URE 5 that the cross-talk characteristics be still further improved by molding the conductive board so as to include an additionalpartitioning structure 78 on the side of the board opposite'that engaging partitioning structure 22, thereby isolating the terminals 18 from one another.

' The structure disclosed herein is an example of an arrangement in which the inventive features of this disclosure may be' .utilized, and it may become apparent to one skilled in the art that certain modifications may be made within the spirit of invention as defined by the appended claims.

What is claimed is:

, 1. A modular shielded patchcord programming system comprising:

'(a) afirst board having a plurality of apertures there- (b) a plurality of contact members each of which passes through an aperture and projects beyond said board, said members being aflixed to said board while being electrically insulated from one another;

(c) an electrically conductive partitioning structure in engagement with said first board and electrically shielding contact member portions extending beyond said board; l. v

(d) an additional board which is electrically conductive and which engages said partitioning structure, said additional board being spaced from said first board by said structure and having apertures therein substantially in alignment with those of said first board; and t (e) a coaxial patchcord having a first conductor and a conductive shield cap electrically insulated from said first conductor, said patchcord being inserted into an aperture of said additional board whereby said first conductor engages a contact member portion shielded by said partitioning structure and said shield cap engages the additional board thereby electrically connecting the shield cap'to the additional board.

2. A modular shielded patchcord programming system as set forth in claim 1,wherein said first board is electrically conductive and said contact members are electrically insulated from said board.

3. A modular shielded patchcord programming system as set forth in claim 1, wherein said additional board is a molded conductive plastic.

4. A modular shielded patchcord programming system as set forth -in claim 1, wherein said partitioning structure comprises a grid-like assembly of metallic strips forming compartments within which individual contact member portions are positioned in spaced relationship with respect to said strips.

5. A modular shielded patchcord programming system as set forth in claim 1, wherein said shield cap includes:

(a) a plurality of radially spaced longitudinal slots extending from the forward end of said cap to define a plurality of flexible fingers thereon;

(b) a plurality of spaced circumferential ribs about said cap, at least the forwardmost one of said ribs being positioned on said fingers, said forwardmost circumferential rib being greater in diameter than the other ribs and also greater in diameter than the aperture into which said patchcord is inserted; and

(0) means for terminating the insertion of the patchcord into said aperture after the apex of said for- 6 wardmost rib passes beyond said additional hoard whereby said flexible fingers expand outwardly and the. forwardmost rib engages one of the surfaces of the additional board to lock the patchcordin its fully inserted position. a

6. A modular shielded patchcord programming system as set forth in claim 5, wherein said terminatingmeans comprises a shoulder on said shield cap which engages that surface of the additional board opposite the one which is engaged by the forwardmost rib with the patchcord in its fully inserted position.

7. A modular shielded patchcord programming sys tem as set forth in claim 5, comprising at least three circumferential ribs, at least one of said ribs other than the forwardmost rib being positioned on said fingers and being greater in diameter than said aperture, whereby when the patchcord insertion is terminated, said other ribs engage the interior of the additional board within the aperture to align said patchcord and to provide a low resistance electrical path between the shield cap and the additional board.

8. A modular shielded patchcord programming system comprising:

(a) a first electrically conductive hoard having a plurality of apertures therein;

(b) a plurality of contact members each of which passes through, and projects beyond, insulating material within individual apertures whereby said mem bers are afi'ixed to said board while being electrically insulated therefrom;

(c)' an electrically conductive partitioning structure in engagement with said conductive board and electrically shielding contact member portions project-- ing beyond said insulating material;

(d) an additional electrically conductive board engaging said partitioning structure and spaced from said first board by said structure, said additional board having apertures therein substantially in alignment with those of said first board; and

(e) a coaxial patchcord having a first conductor and a conductive shield cap electrically insulated from said first conductor, said patchcord being inserted into an aperture of said additional conductive board whereby said first conductor engages a contact member portion shielded by said partitioning structure and said shield cap engages the additional conductive board thereby electrically connecting said shield cap through said additional board and the partitionmg structure to said first board.

9. A modular shielded patchcord programming system as set forth in claim 8, wherein at least one of said conductive boards is a molded conductive plastic.

10. A modular shielded patchcord programming system as set forth in claim 8, wherein said partitioning structure comprises a grid-like assembly of metallic strips forming compartments within which individual contact member portions are positioned in spaced relationship With respect to said strips.

11. A modular shielded patchcord programming system as set forth in claim 8, wherein said shield cap includes:

(a) a plurality of radially spaced longitudinal slots extending from the forward end of said cap to define a plurality of flexible fingers thereon;

(b) a plurality of spaced circumferential ribs about said cap, at least the forwardmost one of said ribs being positioned on said fingers, said forwardmost circumferential rib being greater in diameter than the other ribs and also greater in diameter than the aperture into which said patchcord is inserted; and

(c) means for terminating the insertion of the patchcord into said aperture after the apex of said forwardmost rib passes beyond said additional board whereby said flexible fingers expand outwardly and the forwardmost rib engages one of the surfaces of the additional board to lock the patchcord in its fully inserted position.

12. A modular shielded patchcord programming system as set forth in claim 11, wherein said terminating means comprises a shoulder on said shield cap which engages that surface of the additional board opposite the one which is engaged by the forwardmost rib with the patchcord in its fully inserted position.

13. A modular shielded patchcord programming system as set forth in claim 11, comprising at least three circumferential ribs, at least one of said ribs other than the forwardmost rib being positioned on said fingers and being greater in diameter than said aperture, whereby when the patchcord insertion is terminated, said other ribs engage the interior of the additional board within the aperture to align said patchcord and to provide a low resistance electrical path between the shield cap and the additional board.

14. In a modular shielded patchcord programming system of.the type in which a coaxial patchcord is inserted into a modular contact unit to engage a contact member therein, the improvement in the modular unit comprising:

(a) a first board having a plurality of apertures therein;

(b) a plurality of contact members each of which passes through an aperture and projects beyond said board, said members being affixed to said board while being electrically insulated from one another;

(c) an electrically conductive partitioning structure in engagement with said first board and electrically shielding contact member portions projecting beyond said board; and

(d) an additional board which is electrically conductive and which engages said partitioning structure, said additional board being spaced from said first board by said structure and having apertures therein substantially in alignment with those of said firstboard.

15. An improved modular unit according to claim 14, wherein said first board is electrically conductive and said contact members are electrically insulated from said board.

16. An improved modular unit according to claim 14, wherein said additional board is a molded conductive plastic.

17. An improved modular unit according to claim 14, wherein said partitioning structure comprises a grid-like assembly of metallic strips forming compartments within which individual contact member portions are positioned in spaced relationship with respect to said strips.

18. An improved modular unit according to claim 15, wherein at least one of said conductive boards is a molded conductive plastic.

19. A modular shielded patchcord programming system as set forth in claim 2, further comprising an additional electrically conductive partitioning structure positioned on the side of said first board opposite that engaging the first-mentioned partitioning structures 20. A modular shielded patchcord programmingsysa tem as set forth in claim 1 wherein said first board'is a molded conductive plastic piece which includes an additional partitioning structure on the side of said first board opposite that engaging the first-mentioned=partitioning structure.

21. A modular shielded patchcord programming system as set forth in claim 8, further comprising an addi= tional electrically conductive partitioning structure positioned on the side of said first board opposite that engaging the first-mentioned partitioning structure.

22. A modular shielded patchcordprogramming-system as set forth in claim 8, wherein saidfirst board is'a molded conductive plastic piece which includes an additional partitioning structure on the side of saidfirst board opposite that engaging the first-mentioned. partitioning structure.

23. An improved modular unit according to claim 15, further comprising an additional electrically conductive partitioning structure positioned on the side of said first board opposite that engaging the first-mentioned partitioning structure.

24. An improved modular=unit according :to claim 14 wherein said first board is a molded conductive plastic piece which includes an additional partitioning structure on the side of said first board opposite that engaging the first-mentioned partitioning structure. 1

References Cited UNITED STATES PATENTS 2,983,895 5/1961 Pasik 339-217 3,076,862 2/ 1963 Lucdicke et al 174-685 3,190,975 6/1965 King 339-18 XR 3,231,663 1/ 1966 Schwartz 174--35.4 3,246,208 4/1966 LeX et a1 339-18 X 3,252,127 5/1966 Woodward 339-217 3,263,023 7/1966 Staley 174-685 3,264,526 8/1966 Wiggerman 317-101 3,288,957 11/1966 Fraley 339-18 X 3,295,092 12/1966 Newman et a1 339-18 MARVIN A. CHAMPION, Primary Examiner. PATRICK A. CLIFFORD, Assistant Exam ner, I 

